Resonating element, resonator, electronic device, electronic apparatus, and moving body

ABSTRACT

A resonating element includes a resonator element that includes a vibrating portion and an excitation electrode provided on both main surfaces of the vibrating portion, an intermediate substrate in which the resonator element is mounted so as to be spaced from the excitation electrode, and a spiral electrode pattern that is provided on at least one main surface of the intermediate substrate, in which the electrode pattern is electrically connected to the excitation electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation patent application of U.S. application Ser. No.13/915,740 filed Jun. 12, 2013, which claims priority to Japanese PatentApplication No. 2012-133533 filed Jun. 13, 2012, all of which areincorporated by reference herein in their entireties.

BACKGROUND

1. Technical Field

The present invention relates to a resonating element, a resonator, anelectronic device, an electronic apparatus, and a moving body.

2. Related Art

In the related art, a surface mounting type electronic device has beenwidely used in which a piezoelectric resonator element where anexcitation electrode is formed on a piezoelectric substrate isair-tightly sealed in a package. Here, the piezoelectric resonatorelement uses an AT cut quartz crystal resonator element or the likewhich performs thickness-shear vibration and employs, for example, athin plate into which a piezoelectric substrate is cut at a cut anglecalled an AT cut, by using the characteristics in which the thin plateinto which the piezoelectric substrate such as a quartz crystal is cutat a predetermined angle and thickness has an inherent resonancefrequency.

For example, a surface mounting type quartz crystal oscillator, in whicha quartz crystal resonator element and electronic parts such assemiconductor circuit elements including an oscillation circuit whichoscillates the quartz crystal resonator element are mounted in the samepackage and are sealed, is used as an electronic device provided withthe quartz crystal resonator element, and is widely used as a referencesource of a frequency or time.

JP-A-2010-50508 discloses a quartz crystal oscillator in which a quartzcrystal resonator is mounted on a pedestal formed by a quartz crystalwhich is disposed on an electronic part and an IC so as to substantiallycover an opening of a recess of a container, in order to solve theproblem that stable frequency-temperature characteristics cannot beobtained since stress distortion occurs due to a difference betweenlinear expansion coefficients of a package material and the quartzcrystal, resulting from an ambient temperature variation if a quartzcrystal resonator element is directly mounted on a package using aconductive adhesive or the like.

FIG. 7 is a circuit diagram illustrating an example of a voltagecontrolled quartz crystal oscillator in the related art. The referencesign X1 indicates a quartz crystal resonator, the reference sign A1indicates an amplifier, the reference signs Ca and Cb indicatecapacitors, the reference sign D1 indicates a variable capacitancediode, the reference sign IN indicates a control voltage input terminal,the reference sign Rd indicates a resistor for applying a controlvoltage, and the reference sign OUT indicates a frequency outputterminal of a voltage controlled quartz crystal oscillator.

In addition, a general equivalent circuit of the quartz crystalresonator X1 is shown in FIG. 8. In FIG. 8, the reference sign L1indicates an equivalent series inductance, the reference sign C1indicates an equivalent series capacitance, the reference sign R1indicates an equivalent series resistance, and the reference sign C0indicates a parallel capacitance.

If a load capacitance (combined capacitance) of a circuit side includingthe amplifier A1, viewed from the quartz crystal resonator X1 is set toCL, and a capacitance ratio is set to γ(C0/C1), a variation Δf/f0 of theresonance frequency f0 depending on the load capacitance CL isrepresented by the following well-known equation.

Δf/f0=C0/(2γ(C0+CL))

In other words, in relation to a frequency of the voltage controlledquartz crystal oscillator, the resonance frequency thereof variesdepending on a variation in the load capacitance of an oscillation loop.

In addition, the variable capacitance diode D1 is a diode of which acapacitance value varies depending on a reverse voltage applied betweentwo terminals thereof. Therefore, the variable capacitance diode D1 isinserted into the oscillation loop and a voltage applied thereto isvaried, thereby controlling an oscillation frequency.

However, if the quartz crystal resonator is to be miniaturized so as tocorrespond to miniaturization of a recent portable telephone, aninformation terminal or the like, an excitation electrode of a quartzcrystal resonator element is reduced. Therefore, a capacitance of apackage for the equivalent series capacitance C1 or a ratio of floatingcapacitances between electrodes increases, and, as a result, there is aproblem in that the capacitance ratio γ of the quartz crystal resonatorincreases, and thereby a desired frequency variable width cannot beobtained.

As a piezoelectric resonator capable of adjusting the frequency variablewidth, a piezoelectric resonator in which an inductor circuit pattern isprovided in a package and an inductor L is connected to a piezoelectricresonator element accommodated in the package is disclosed in, forexample, JP-A-2-226905. The inductor L which is inserted into theoscillation loop for this purpose is generally called an extension coil(or, simply a “coil”). This is based on a principle that, when theinductor L is connected in series to the piezoelectric resonator X1, aresonance frequency becomes lower than a frequency before the inductor Lis inserted, but an antiresonance frequency does not vary, and thus aninterval between the resonance frequency and the antiresonance frequencybecomes spread.

However, in the piezoelectric resonator disclosed in JP-A-2-226905, adedicated package in which the inductor circuit pattern is provided isnecessary, and thus there is a problem in that a package does not haveversatility.

SUMMARY

An advantage of some aspects of the invention is to solve at least apart of the problems described above and the invention can beimplemented as the following forms or application examples.

Application Example 1

This application example is directed to a resonating element including aresonator element that includes a vibrating portion and an excitationelectrode provided on both main surfaces of the vibrating portion; anintermediate substrate in which the resonator element is mounted so asto be spaced from the excitation electrode; and a spiral electrodepattern that is provided on the intermediate substrate, in which theelectrode pattern is electrically connected to the excitation electrode.

According to this application example, when the resonating element has astructure in which the resonator element which is stably excited ismounted on the intermediate substrate, and is thus mounted in a package,the intermediate substrate reduces stress distortion due to a differencefrom a linear expansion coefficient of the package so as to obtainstable frequency-temperature characteristics. In addition, there is aneffect of obtaining a desired frequency variable width in a case offorming an oscillator since an inductance is given by the spiralelectrode pattern formed on the intermediate substrate even if acapacitance ratio 7 increases according to miniaturization.

Application Example 2

This application example is directed to the resonating element accordingto the application example described above, wherein the electrodepattern and the excitation electrode are connected in series or inparallel to each other.

According to this application example, the series connection correspondsto inserting an inductor into an oscillation loop of the oscillator, andthereby there is an effect of increasing a frequency variable width. Inaddition, the parallel connection achieves an effect that it is possibleto suppress influence of an unnecessary capacitance such as a floatingcapacitance between electrodes in the oscillator.

Application Example 3

This application example is directed to the resonating element accordingto the application example described above, wherein the electrodepattern and the excitation electrode are disposed so as not to overlapeach other in plan view.

According to this application example, the excitation electrode and theelectrode pattern for inductance do not overlap each other, and therebyit is possible to prevent adverse effects caused by a floatingcapacitance between electrodes of the excitation electrode and theelectrode pattern for inductance from being exerted on oscillationcharacteristics.

Application Example 4

This application example is directed to the resonating element accordingto the application example described above, wherein the electrodepatterns are provided on both main surfaces of the intermediatesubstrate, and the electrode patterns are connected in series to eachother.

According to this application example, it is possible to make aninductance large and to thereby increase more effectively a frequencyvariable width since the length of the electrode patterns can increasewithout increasing the size of the intermediate substrate as comparedwith a case where an electrode pattern for inductance is provided onlyone main surface of the intermediate substrate.

Application Example 5

This application example is directed to the resonating element accordingto the application example described above, wherein the electrodepattern is provided on one main surface of both main surfaces of theintermediate substrate which are front and rear surfaces, a shieldelectrode is provided on the other main surface, and the other mainsurface is opposite to the excitation electrode.

According to this application example, the shield electrode is providedbetween the excitation electrode and the electrode pattern forinductance, and thereby it is possible to prevent adverse effects causedby a floating capacitance between electrodes of the excitation electrodeand the electrode pattern for inductance from being exerted onoscillation characteristics.

Application Example 6

This application example is directed to the resonating element accordingto the application example described above, wherein the resonatorelement includes the vibrating portion; and an outer edge portion thatis integrally formed with an outer edge of the vibrating portion and isthinner than the vibrating portion.

According to this application example, since the vibrating portion ofthe resonator element has a mesa structure, coupling with a spuriousprofile can be prevented, and thus vibration energy of only the mainvibration can be confined. Therefore, it is possible to provide aresonating element in which CI is small and a spurious frequency arounda resonance frequency is suppressed.

Application Example 7

This application example is directed to the resonating element accordingto the application example described above, wherein the resonatorelement includes the vibrating portion; and an outer edge portion thatis integrally formed with an outer edge of the vibrating portion and isthicker than the vibrating portion.

According to this application example, since even a high frequencyresonating element in which the vibrating portion of the resonatorelement is very thin can be mounted on the thick part which isintegrally formed with the vibrating portion, it is possible to providea resonating element with good resistance to impact or resistance tovibration.

Application Example 8

This application example is directed to a resonator including theresonating element according to the application example described above;and a package in which the resonating element is mounted by includingthe intermediate substrate mounted therein.

According to this application example, the resonating element isaccommodated in the package, and thereby it is possible to preventinfluence of disturbance such as a temperature variation, a humidityvariation or influence due to contamination. Therefore, there is aneffect that it is possible to provide a resonator which has goodfrequency reproducibility, frequency-temperature characteristics,CI-temperature characteristics, and frequency aging characteristics andhas thus a large frequency variable width.

Application Example 9

This application example is directed to an electronic device includingthe resonating element according to the application example describedabove; a package in which the resonating element is mounted by includingthe intermediate substrate mounted therein; and an oscillation circuitthat excites the vibrating portion.

According to this application example, since the resonating elementhaving an inductance is used, there is an effect that it is possible toprovide an electronic device such as a voltage controlled oscillatorhaving good frequency-temperature characteristics and a large frequencyvariable width.

Application Example 10

This application example is directed to an electronic device includingthe resonating element according to the application example describedabove; a package in which the resonating element is mounted by includingthe intermediate substrate mounted therein; and an oscillation circuitthat excites the vibrating portion, in which the shield electrode isconnected to a ground terminal of the package.

According to this application example, when the quartz crystalresonating element which has the shield electrode between the excitationelectrode and the electrode pattern for inductance is mounted in apackage, the shield electrode of the quartz crystal resonating elementis connected to a ground terminal of the oscillator, and thereby thereis an effect that it is possible to prevent adverse effects caused by afloating capacitance between electrodes of the excitation electrode andthe electrode pattern for inductance from being exerted on oscillationcharacteristics.

Application Example 11

This application example is directed to an electronic apparatusincluding the resonating element according to the application exampledescribed above.

According to this application example, there is an effect that anelectronic apparatus having a favorable reference frequency source canbe formed using the resonating element with good frequency-temperaturecharacteristics.

Application Example 12

This application example is directed to a moving body including theresonating element according to the application example described above.

According to this application example, there is an effect that a stablereference frequency source can be formed, and thus a moving bodyincluding a stable and accurate electronic control unit can be formed,using the resonating element with good frequency-temperaturecharacteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIGS. 1A and 1B are schematic diagrams illustrating a structure of aresonator element according to a first embodiment of the invention, inwhich FIG. 1A is a plan view when viewed from the top, and FIG. 1B is across-sectional view taken along the line A-A.

FIGS. 2A to 2C are schematic diagrams illustrating a structure of anintermediate substrate according to the first embodiment of theinvention, in which FIG. 2A is a plan view when viewed from the top,FIG. 2B is a cross-sectional view taken along the line B-B, and FIG. 2Cis a plan view when viewed from the bottom.

FIGS. 3A and 3B are schematic diagrams illustrating a structure of aresonating element according to the first embodiment of the invention,in which FIG. 3A is a plan view when viewed from the top, and FIG. 3B isa cross-sectional view taken along the line C-C.

FIGS. 4A and 4B are schematic diagrams illustrating a structure of aresonator according to the first embodiment of the invention, in whichFIG. 4A is a plan view when viewed from the top, and FIG. 4B is across-sectional view taken along the line N-N.

FIGS. 5A and 5B are schematic diagrams illustrating a structure of anelectronic device according to the first embodiment of the invention, inwhich FIG. 5A is a plan view when viewed from the top, and FIG. 5B is across-sectional view taken along the line D-D.

FIG. 6 is a circuit diagram illustrating an example of a circuit of anoscillator.

FIG. 7 is a circuit diagram illustrating an example of a voltagecontrolled quartz crystal oscillation circuit as an oscillator in therelated art.

FIG. 8 is a circuit diagram illustrating an example of an equivalentcircuit of a quartz crystal resonator.

FIGS. 9A to 9C are schematic diagrams illustrating a structure of anintermediate substrate according to a second embodiment of theinvention, in which FIG. 9A is a plan view when viewed from the top,FIG. 9B is a cross-sectional view taken along the line E-E, and FIG. 9Cis a plan view when viewed from the bottom.

FIGS. 10A and 10B are schematic diagrams illustrating a structure of aresonating element according to the second embodiment of the invention,in which FIG. 10A is a plan view when viewed from the top, and FIG. 10Bis a cross-sectional view taken along the line F-F.

FIGS. 11A to 11C are schematic diagrams illustrating a structure of anintermediate substrate according to a third embodiment of the invention,in which FIG. 11A is a plan view when viewed from the top, FIG. 11B is across-sectional view taken along the line G-G, and FIG. 11C is a planview when viewed from the bottom.

FIGS. 12A and 12B are schematic diagrams illustrating a structure of aresonating element according to the third embodiment of the invention,in which FIG. 12A is a plan view when viewed from the top, and FIG. 12Bis a cross-sectional view taken along the line H-H.

FIGS. 13A to 13C are schematic diagrams illustrating a structure of anintermediate substrate according to a fourth embodiment of theinvention, in which FIG. 13A is a plan view when viewed from the top,FIG. 13B is a cross-sectional view taken along the line I-I, and FIG.13C is a plan view when viewed from the bottom.

FIGS. 14A and 14B are schematic diagrams illustrating a structure of aresonating element according to the fourth embodiment of the invention,in which FIG. 14A is a plan view when viewed from the top, and FIG. 14Bis a cross-sectional view taken along the line J-J.

FIGS. 15A and 15B are schematic diagrams illustrating a structure of anelectronic device according to the fourth embodiment of the invention,in which FIG. 15A is a plan view when viewed from the top, and FIG. 15Bis a cross-sectional view taken along the line K-K.

FIGS. 16A and 16B are schematic diagrams illustrating a structure of aresonator element according to a fifth embodiment of the invention, inwhich FIG. 16A is a plan view when viewed from the top, and FIG. 16B isa cross-sectional view taken along the line L-L.

FIGS. 17A and 17B are schematic diagrams illustrating a structure of aresonating element according to the fifth embodiment of the invention,in which FIG. 17A is a plan view when viewed from the top, and FIG. 17Bis a cross-sectional view taken along the line M-M.

FIGS. 18A and 18B are schematic diagrams illustrating a structure of aresonator element according to a sixth embodiment of the invention, inwhich FIG. 18A is a plan view when viewed from the top, and FIG. 18B isa cross-sectional view taken along the line O-O.

FIGS. 19A and 19B are schematic diagrams illustrating a structure of aresonating element according to the sixth embodiment of the invention,in which FIG. 19A is a plan view when viewed from the top, and FIG. 19Bis a cross-sectional view taken along the line P-P.

FIG. 20 is a perspective view illustrating a configuration of a mobiletype (or a notebook type) personal computer which is an electronicapparatus including the resonating element according to the firstembodiment of the invention.

FIG. 21 is a perspective view illustrating a configuration of a mobilephone (including PHS) which is an electronic apparatus including theresonating element according to the first embodiment of the invention.

FIG. 22 is a perspective view illustrating a configuration of a digitalcamera which is an electronic apparatus including the resonating elementaccording to the first embodiment of the invention.

FIG. 23 is a perspective view illustrating a configuration of anautomobile which is a moving body to which the resonator or theelectronic device including the resonating element according to thefirst embodiment of the invention is applied.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the invention will be described in detailwith reference to the drawings.

Resonator Element

FIG. 1A is a schematic plan view when an example of a quartz crystalresonator element which is a resonator element according to a firstembodiment of the invention is viewed from the top, and FIG. 1B is across-sectional view taken along the line A-A of FIG. 1A.

A quartz crystal resonator element 1 which is formed using a quartzcrystal is formed using, for example, a quartz crystal wafer which is asingle-crystalline substrate which is cut at a predetermined cut anglefrom a quartz crystal Lambert in which some of synthetic quartz crystalore is formed on a block by clarifying a crystal axis (optical axis)thereof. Here, the predetermined cut angle indicates a cut angle whichis tilted by a desired angle with respect to the crystal axis of thequartz crystal, and, in the present embodiment, a description will bemade of the quartz crystal resonator element 1 which is formed using aso-called AT cut quartz crystal cut at a cut angle tilted by 35° 15′from the crystal axis and shows a thickness-shear vibration mode. Thequartz crystal resonator element 1 using this AT cut quartz crystal is apiezoelectric resonator element with good temperature characteristicswhich can provide a stable frequency in a wide temperature region.

The quartz crystal resonator element 1 includes, as shown in FIG. 1A, aquartz crystal substrate 10, excitation electrodes 20 a and 20 b, andexternal connection terminals 22 a and 22 b. The quartz crystalsubstrate 10 includes a support portion 14 which is a fixed end (theleft side of the quartz crystal resonator element 1 in FIGS. 1A and 1B)and a vibrating portion 12 which is a free end (one end (the right sideof the quartz crystal resonator element 1 in FIGS. 1A and 1B) on a sideof the quartz crystal resonator element 1 which is not fixed). Thesupport portion 14 indicates a region between the vibrating portion 12and the fixed end (the left side) of the quartz crystal resonatorelement 1. A pair of excitation electrodes 20 a and 20 b are provided soas to be opposite to each other on both main surfaces of the vibratingportion 12. In addition, the external connection terminals 22 a and 22 bwhich respectively correspond to the excitation electrodes 20 a and 20 bare provided on both main surfaces of the support portion 14, and theexcitation electrodes 20 a and 20 b are respectively electricallyconnected to the corresponding to external connection terminals 22 a and22 b via lead electrodes 21 a and 21 b. In addition, the externalconnection terminals 22 a and 22 b provided so as to be opposite to eachother on both the main surfaces of the support portion 14 arerespectively electrically connected to each other via side electrodes 23a and 23 b.

The quartz crystal substrate 10 is etched so as to form an exterior ofthe quartz crystal resonator element 1, and, then, a metal film using,for example, gold (Au), is formed on a ground layer of, for example,nickel (Ni) or chrome (Cr) through deposition or sputtering and issubsequently patterned using photolithography, thereby forming theelectrode pattern of the electrodes, the terminals, and the like.

In the embodiment shown in FIG. 1A, an example in which shapes of theexcitation electrodes 20 a and 20 b are rectangular has been described,but shapes of the excitation electrodes 20 a and 20 b are not limitedthereto and may be circular or elliptical.

Intermediate Substrate

FIG. 2A is a schematic plan view when an intermediate substrateaccording to the first embodiment of the invention is viewed from thetop, FIG. 2B is a cross-sectional view taken along the line B-B of FIG.2B, and FIG. 2C is a schematic plan view when FIG. 2A is viewed from thebottom.

An intermediate substrate 2 includes, as shown in FIGS. 2A to 2C, asubstrate 15, an electrode pattern 30 for inductance, terminals 32 a and32 b for joining to the quartz crystal resonator element 1, andconnection terminals 34 a and 34 b. The substrate 15 includes a baseportion 17, a joining region to the quartz crystal resonator element 1,and an inductance forming region (a region in which the spiral electrodepattern 30 is formed) which are integrally formed in an arranged stateon the plane. In addition, if the substrate 15 is formed of a quartzcrystal substrate which is an insulating material and has the same cutangle as the quartz crystal resonator element 1, there is no differencein the linear expansion coefficient, and thus stress distortion causedby joining to the quartz crystal resonator element 1 does not occur,thereby obtaining stable frequency-temperature characteristics.

The base portion 17 is a portion which is fixed when a quartz crystalresonating element 3 in which the quartz crystal resonator element 1overlaps the intermediate substrate 2 is joined to a package (refer toFIGS. 4A to 5B), and is provided with the connection terminals 34 a and34 b used for electrical connection between the quartz crystal resonatorelement 1, the electrode pattern 30 for inductance, and the package. Inaddition, the connection terminals 34 a and 34 b which are provided soas to be opposite to each other on both main surfaces of the baseportion 17 are respectively electrically connected to each other viaside electrodes 35 a and 35 b.

As shown in FIG. 2A, one main surface of the substrate 15 is a surfaceon which the quartz crystal resonator element 1 is mounted, and isprovided with the joining terminals 32 a and 32 b and the electrodepattern 30 for inductance. The connection terminal 34 a is electricallyconnected to the terminal 32 a for joining to the quartz crystalresonator element 1 via a lead electrode 33. In addition, the terminal32 b for joining to the quartz crystal resonator element 1 iselectrically connected to the electrode pattern 30 for inductance via alead electrode 31. The electrode pattern 30 for inductance is aninductor which is inserted into an oscillation loop of an oscillationcircuit such as a quartz crystal oscillator and is generally called anextension coil or simply a coil. The electrode pattern 30 for inductanceof the present embodiment is formed as a coil in which a thin and longwire is directed to the inner circumference from the outer circumferenceso as to have a rectangular spiral shape in the induction forming regionon one main surface of the substrate 15. In addition, a shape of theelectrode pattern 30 for inductance is not limited thereto, and may be ashape in which a distance from a start end to a finish end of aninductance pattern using a wire is as long as possible, for example, atypical spiral shape with an arc. Further, the electrode pattern 30 forinductance may be formed as a coil with a shape which is folded manytimes from one end part to the other part.

In addition, as shown in FIG. 2C, the other main surface of thesubstrate 15 is a surface on a side which is joined to a package in thequartz crystal resonator or the quartz crystal oscillator of the presentembodiment (refer to FIGS. 4A to 5B). A lead electrode 36 is drawn outfrom the connection terminal 34 b toward the inductance forming region,is led up to directly under the central end part of the electrodepattern 30 for inductance provided on one main surface, and iselectrically connected to the electrode pattern 30 for inductance via anin-layer pattern 37 such as a through-hole. Thereby, a single inductoris formed by the electrode pattern 30 for inductance between theterminal 32 b for joining to the quartz crystal resonator element 1provided on one main surface in the base portion 17 of the substrate 15and the connection terminal 34 b provided in the base portion 17. Inaddition, in the present embodiment, in order to increase a frequencyvariable width of the oscillator, the quartz crystal resonator element 1is connected in series to the electrode pattern 30 for inductance, theinvention is not limited thereto, and the quartz crystal resonatorelement 1 may be connected in parallel to the electrode pattern 30 forinductance in order to suppress an unnecessary capacitance such as afloating capacitance between the respective electrodes in theoscillator.

Resonating Element

Next, a description will be made of a resonating element in which thequartz crystal resonator element 1 and the intermediate substrate 2according to the present embodiment are stacked and are joined to eachother with reference to the drawings.

FIG. 3A is a schematic plan view when an example of a quartz crystalresonating element which is a resonating element according to the firstembodiment of the invention is viewed from the top, and FIG. 3B is across-sectional view taken along the line C-C of FIG. 3A.

As shown in FIGS. 3A and 3B, the quartz crystal resonating element 3 isformed by mounting the quartz crystal resonator element 1 on theintermediate substrate 2. The terminals 32 a and 32 b for joining to thequartz crystal resonator element 1 provided on one main surface of theintermediate substrate 2 are aligned with the corresponding externalconnection terminals 22 a and 22 b and are joined thereto via a joiningmember 40. The joining member 40 uses a conductive joining member 40such as a conductive adhesive or solder, and thereby mechanical joiningcan be performed along with electrical connection. In addition, thevibrating portion 12 of the quartz crystal resonator element 1 isdisposed with a gap by the joining member 40 with respect to one mainsurface of the intermediate substrate 2 on which the electrode pattern30 for inductance is formed.

In addition, if the substrate 15 of the intermediate substrate 2 isformed of a quartz crystal substrate having the same cut angle as thequartz crystal resonator element 1, there is no difference in the linearexpansion coefficient, and stress distortion occurring when the quartzcrystal resonator element 1 and the intermediate substrate 2 are stackedand are joined is small. Therefore, there is an effect that a resonatingelement having stable frequency-temperature characteristics can beobtained.

Resonator

FIG. 4A is a schematic plan view when an example of a quartz crystalresonator which is a resonator according to the first embodiment of theinvention is viewed from the top, and FIG. 4B is a cross-sectional viewtaken along the line N-N of FIG. 4A. In addition, in FIGS. 4A and 4B,for convenience of description of an inner configuration of the quartzcrystal resonator, a state in which a lid member is removed is shown.

A quartz crystal resonator 4 includes the quartz crystal resonatingelement 3, a package main body 60 which is formed in a rectangular boxshape so as to accommodate the quartz crystal resonating element 3, anda lid member 70 made of metal, ceramic, glass, or the like.

The package main body 60, as shown in FIG. 4B, is formed by stacking afirst substrate 61, a second substrate 62, a sealing 68, and a mountingterminal 86. The mounting terminal 86 is formed in plurality on an outerbottom of the first substrate 61. The second substrate 62 is aring-shaped body of which the center is removed, and the sealing 68 suchas, for example, Kovar is formed on the upper rim of the secondsubstrate 62.

A cavity 65 which accommodates the quartz crystal resonating element 3is formed by the second substrate 62. A plurality of element mountingpads 81 which are electrically connected to the mounting terminals 86 byconductors (not shown) formed inside the first substrate 61 are providedat predetermined positions of the upper surface of the first substrate61. The element mounting pads 81 are disposed so as to correspond to theconnection terminals 34 a and 34 b formed in the base portion 17 of theintermediate substrate 2 when the quartz crystal resonating element 3 isplaced.

The above-described first substrate 61 and second substrate 62 of thepackage main body 60 are made of a ceramic insulating material or thelike. In addition, the respective electrodes, terminals, wire patternsor in-layer wire patterns electrically connecting the electrodes or theterminals to each other, or the like provided in the package main body60 are generally formed by screen-printing a metal wire material such astungsten (W) or molybdenum (Mo) on a ceramic insulating material so asto be baked at high temperature, and by performing plating such asnickel (Ni) or gold (Au) thereon.

If the quartz crystal resonating element 3 is to be supported and fixed(mounted), first, a joining member 42 and a joining member 44, forexample, conductive adhesives are coated at positions corresponding tothe element mounting pads 81 which correspond to the connectionterminals 34 a and 34 b of the quartz crystal resonating element 3 andthe end part (the right side of the quartz crystal resonating element 3in FIGS. 4A and 4B) on the opposite side to the base portion 17 of theintermediate substrate 2 forming the quartz crystal resonating element3, and a load is applied thereto by placing the connection terminals 34a and 34 b of the quartz crystal resonating element 3 and the end partof the intermediate substrate 2 of the quartz crystal resonating element3 thereon.

Next, the joining member 42 and the joining member 44 are put inside ahigh temperature furnace of a predetermined temperature for apredetermined time so as to be cured. The joining member 42 and thejoining member 44 are cured and then undergo an annealing process, and afrequency is adjusted by adding the mass to the excitation electrode 20a or by reducing the mass. Thereafter, the lid member 70 is placed onthe sealing 68 formed on the upper surface of the second substrate 62 ofthe package main body 60, and the lid member 70 is sealed through seamwelding in vacuum or in a nitrogen gas atmosphere such that the quartzcrystal resonator 4 is completed. Alternatively, there may be a methodin which the lid member 70 is placed on low melting glass coated on theupper surface of the package main body 60 and is melted so as to becohered. Also in this case, the cavity 65 of the package main body 60 ismade to be vacuum, or is filled with an inert gas such as a nitrogengas, thereby completing the quartz crystal resonator 4.

In addition, in the present embodiment, an example of using a conductiveadhesive as the joining member 44 has been described, but, in a casewhere electrical connection is not necessary, a non-conductive adhesivemay be used. Further, the end part on the opposite side to theconnection terminals 34 a and 34 b of the quartz crystal resonatingelement 3 is joined in order to increase the mounting strength of thequartz crystal resonating element 3, but the invention is not limitedthereto, and the end part may not be joined.

Electronic Device

FIG. 5A is a schematic plan view when an example of a quartz crystaloscillator which is an electronic device according to the firstembodiment of the invention is viewed from the top, and FIG. 5B is across-sectional view taken along the line D-D of FIG. 5A. In addition,in FIGS. 5A and 5B, for convenience of description of an innerconfiguration of the quartz crystal oscillator, a state in which the lidmember is removed is shown.

A quartz crystal oscillator 5 includes a package main body 60 a, the lidmember 70, the quartz crystal resonating element 3, and an IC chip 50 inwhich an oscillation circuit exciting the quartz crystal resonatingelement 3 is mounted.

The quartz crystal oscillator 5 according to the present embodiment is aone-chip quartz crystal oscillator of a so-called Surface Mount Device(SMD) type in which the IC chip 50 including the quartz crystalresonator element 1 and the oscillation circuit is joined to the innercavity 65 of the package main body 60 a and is sealed, and surfacemounting is possible. In addition, the SMD type quartz crystaloscillator 5 which is standardized as a surface mount part isadvantageous to simplification of mounting processes or low costs, sinceit is not necessary to cut or mold a lead wire for external connectionso as to conform with a connection terminal shape of an externalsubstrate, and automation for mounting on an external substrate iseasily performed, for example, unlike a type of quartz crystal resonatorin which a quartz crystal resonator element joined to a substrate iscovered with a cylindrical cap so as to be sealed.

As shown in FIG. 5B, the package main body 60 a is formed by stacking afirst substrate 61, a second substrate 62, a third substrate 63, asealing 68, and a mounting terminal 86. The mounting terminal 86 isformed in plurality on the outer bottom of the first substrate 61. Thesecond substrate 62 and the third substrate 63 are ring-shaped bodies ofwhich the center is removed, and the sealing 68 such as Kovar is formedon the upper rim of the second substrate 62.

A cavity 65 which accommodates the quartz crystal resonating element 3and a recess 66 which accommodates the IC chip 50 in which theoscillation circuit exciting the quartz crystal resonating element 3 ismounted are formed by the second substrate 62 and the third substrate63. The upper surface of the first substrate 61 which is a bottom of therecess 66 is provided with a plurality of IC joining terminals 84 towhich the IC chip 50 is connected. A plurality of element mounting pads81 which are electrically connected to the mounting terminals 86 byconductors (not shown) formed inside the first substrate 61 and thethird substrate 63 are provided at predetermined positions of the uppersurface of the third substrate 63. The element mounting pads 81 aredisposed so as to correspond to the connection terminals 34 a and 34 bformed in the base portion 17 of the intermediate substrate 2 when thequartz crystal resonating element 3 is placed.

The above-described first substrate 61 to the third substrate 63 of thepackage main body 60 a are made of a ceramic insulating material or thelike. In addition, the respective electrodes, terminals, wire patternsor in-layer patterns electrically connecting the electrodes or theterminals to each other, or the like, provided in the package main body60 a are generally formed by screen-printing a metal wire material suchas tungsten (W) or molybdenum (Mo) on a ceramic insulating material soas to be baked at high temperature, and by performing plating such asnickel (Ni) or gold (Au) thereon.

In FIG. 5B, the IC chip 50 which is a semiconductor circuit elementincluding an excitation circuit for exciting and resonating the quartzcrystal resonator element 1 is joined to the IC joining terminals 84provided at the bottom of the recess 66 of the package main body 60 a,for example, using a brazing filler metal or an adhesive. In the presentembodiment, the IC chip 50 is joined onto the IC joining terminals 84 ina face-down manner by bumps 46 which are made of a metal or a solderprovided in electrode pad (not shown) of the IC chip 50 in advance. Thejoining of the IC chip 50 through the face-down joining is advantageousto thinning (low height) of the quartz crystal oscillator 5. Inaddition, after the IC chip 50 is joined in a face-down manner by thebumps 46, a gap between the IC chip 50 and the bottom of the recess 66of the package main body 60 a is filled with an under-filling materialwhich is cured, so as to further increase the joining strength of the ICchip 50. Further, joining of the IC chip 50 to the package main body 60a is not limited to the face-down joining, and may be performed usingother IC mounting techniques such as wire bonding.

The quartz crystal resonating element 3 in which the quartz crystalresonator element 1 is joined onto the intermediate substrate 2 isjoined using conductive joining member 42 and joining member 44 such asconductive adhesives in the cavity 65 of the package main body 60 a in astate in which the connection terminals 34 a and 34 b of theintermediate substrate 2 are aligned with the corresponding elementmounting pads 81. In addition, positions or the number of the elementmounting pads 81 are not limited to the aspect shown in FIGS. 5A and 5B,and may be appropriately varied depending on a connection relationshipbetween the quartz crystal resonator element 1 and the electrode pattern30 for inductance, and a connection relationship between the quartzcrystal resonating element 3 and the IC chip 50. Further, a connectionbetween the quartz crystal resonating element 3 and the element mountingpads 81 is also not limited to the face-down joining, and may be aconnection using wire bonding, or may be a connection using acombination of the face-down joining and the wire bonding. Furthermore,direct wire bonding may be performed between the terminals 32 a and 32 bfor joining to the quartz crystal resonator element 1 and the elementmounting pads 81.

Thereby, the IC chip 50 including oscillation circuit oscillating thequartz crystal resonator element 1 can be connected in series to thequartz crystal resonator element 1 via the electrode pattern 30 forinductance of the intermediate substrate 2 interposed therebetween. FIG.6 is a circuit diagram illustrating an example of a circuit in which theelectrode pattern 30 for inductance is interposed between the quartzcrystal resonator element 1 and the IC chip 50 in the quartz crystaloscillator. As shown in FIG. 6, in the quartz crystal oscillator, the ICchip 50 includes terminals 50 a and 50 b, and, in the series circuit ofthe quartz crystal resonator element 1 and the electrode pattern 30 forinductance between the two terminals, the quartz crystal resonatorelement 1 may be connected to the terminal 50 a and the electrodepattern 30 for inductance may be connected to the terminal 50 b.

In addition, the quartz crystal resonator element 1 is disposed in thepackage main body 60 a with the intermediate substrate 2 including theelectrode pattern 30 for inductance interposed between the quartzcrystal resonator element 1 and the IC chip 50.

In addition, of the joining member 42 and the joining member 44 used forjoining between the quartz crystal resonating element 3 and the packagemain body 60 a, the conductive joining member 42 may use a conductiveadhesive or the like in which, for example, polyimide, or a resin suchas a silicon-based or epoxy-based resin is mixed with silver (Ag)filament or nickel (Ni) powder.

The lid member 70 is joined onto the second substrate 62 of the packagemain body 60 a in which the IC chip 50 and the quartz crystal resonatingelement 3 are joined together. Specifically, the lid member 70 which ismade of a metal such as 42Alloy (an alloy in which nickel of 42% iscontained in iron) or Kovar (an alloy of iron, nickel, and cobalt) isseam-welded via the sealing 68 which is formed by cutting a iron-nickel(Fe—Ni) alloy or the like in a frame shape. In addition, the lid member70 may use ceramic, glass, or the like in addition to theabove-described metal, and, for example, in a case where the lid member70 made of glass is used, a joining member may be appropriately selecteddepending on a material of the lid member 70 such as using low meltingglass as a joining member, and thereby the package main body 60 a may bejoined to the lid member 70.

The cavity 65 formed by the package main body 60 a and the lid member 70is a space for the quartz crystal resonator element 1 being operated.The cavity 65 may be sealed airtightly in a decompressed space or in aninert gas atmosphere in the quartz crystal oscillator 5 according to thepresent embodiment. For example, in a case where the cavity 65 is sealedairtightly in a compressed space, the quartz crystal oscillator 5 isplaced in a vacuum chamber in a state in which a solid sealing materialis disposed in a sealing hole (not shown) of the package main body 60 a,and is decompressed up to a predetermined degree of vacuum so as toexhaust a gas emitted from inside of the quartz crystal oscillator 5through the sealing hole, and then the solid sealing material is meltedand is cured so as to close the sealing hole, thereby sealing the cavity65. Thereby, the quartz crystal resonator element 1 and the IC chip 50joined in the recess 66 of the package main body 60 a can be airtightlysealed.

In addition, the sealing material preferably has, as a melting point, atemperature higher than a reflow temperature when the completed quartzcrystal oscillator 5 is mounted on an external mounting substrate, andmay use, for example, an alloy of gold and tin (Sn), an alloy of goldand germanium (Ge), or the like.

According to the quartz crystal oscillator 5 of the above-describedembodiment, the IC chip 50 which is a semiconductor circuit elementincluding the oscillation circuit and the electrode pattern 30 forinductance connected to the quartz crystal resonator element 1 which isa piezoelectric resonator element are provided inside the package mainbody 60 a, and thus it is possible to provide the quartz crystaloscillator 5 which is a one-chip piezoelectric oscillator having highreliability and a large frequency variable width due to the one-sealstructure.

Particularly, in the quartz crystal oscillator 5 of the above-describedembodiment, the electrode pattern 30 for inductance is connected inseries to the quartz crystal resonator element 1, and thus it ispossible to more notably achieve an effect of increasing a frequencyvariable width by inserting an inductor into the oscillation loop of thequartz crystal oscillator 5.

In addition, since the quartz crystal resonator element 1 is mounted onthe intermediate substrate 2 in which the electrode pattern 30 forinductance is formed, it is possible to provide the one-chip quartzcrystal oscillator 5 of which oscillation characteristics are stable byusing a general purpose package.

Further, since the intermediate substrate 2 in which the electrodepattern 30 for inductance is disposed between the IC chip 50 and thequartz crystal resonator element 1, the intermediate substrate 2achieves a shield effect, and thus it is possible to suppress influencecaused by a floating capacitance between the electrodes of the IC chip50 and the quartz crystal resonator element 1 from being exerted onoscillation characteristics.

Modification Example 1 of Intermediate Substrate

FIGS. 9A to 9C show a modification example of the intermediate substrateshown in FIGS. 2A to 2C, in which FIG. 9A is a schematic plan view whena structure of the intermediate substrate according to a secondembodiment of the invention is viewed from the top, FIG. 9B is across-sectional view taken along the line E-E of FIG. 9A, and FIG. 9C isa schematic plan view when FIG. 9A is viewed from the bottom.

An intermediate substrate 102 according to the present modificationexample includes, as shown in FIGS. 9A to 9C, a substrate 115, anelectrode pattern 130 for inductance, terminals 132 a and 132 b forjoining to the quartz crystal resonator element 1, and connectionterminals 134 a and 134 b, and has the same configuration as theintermediate substrate 2 of the embodiment shown in FIGS. 2A to 2C.However, a gap between the electrode pattern 130 for inductance and theterminals 132 a and 132 b for joining to the quartz crystal resonatorelement 1 is substantially the same length as the length of the quartzcrystal resonator element 1.

One main surface of the substrate 115 is a surface on which the quartzcrystal resonator element 1 is mounted, and is provided with theelectrode pattern 130 for inductance, the joining terminals 132 a and132 b, and the connection terminals 134 a and 134 b, which arerespectively electrically connected to each other via lead electrodes131 and 133. In addition, the other main surface of the substrate 115 isprovided with the connection terminals 134 a and 134 b, and a leadelectrode 136 is drawn out from the connection terminal 134 b and iselectrically connected to the electrode pattern 30 for inductanceprovided on one main surface via an in-layer wire 37 using athrough-hole.

Since, in the intermediate substrate 102, a gap between the electrodepattern 130 for inductance and the terminals 132 a and 132 b for joiningto the quartz crystal resonator element 1 is wide, in a case where aquartz crystal resonating element is formed by stacking and joining thequartz crystal resonator element 1 and the intermediate substrate 102,the excitation electrode 20 b of the quartz crystal resonator element 1and the electrode pattern 130 for inductance can be made not to overlapeach other.

Modification Example 1 of Quartz Crystal Resonating Element

FIGS. 10A and 10B show a modification example of the quartz crystalresonating element, in which FIG. 10A is a schematic plan view when astructure of the quartz crystal resonating element according to thesecond embodiment of the invention is viewed from the top, and FIG. 10Bis a cross-sectional view taken along the line F-F of FIG. 10A.

As shown in FIGS. 10A and 10B, a quartz crystal resonating element 103according to the present modification example is formed by mounting thequartz crystal resonator element 1 on the intermediate substrate 102which is a modification example of the intermediate substrate 2 of theembodiment shown in FIGS. 2A to 2C. The terminals 132 a and 132 b forjoining to the quartz crystal resonator element 1 provided on one mainsurface of the intermediate substrate 102 are aligned with thecorresponding external connection terminals 22 a and 22 b of the quartzcrystal resonator element 1 and are joined thereto via a joining member40. In addition, the vibrating portion 12 of the quartz crystalresonator element 1 is disposed with a gap by the joining member 40 withrespect to one main surface of the intermediate substrate 102 on whichthe electrode pattern 130 for inductance is formed.

In the quartz crystal resonating element 103, a gap between theelectrode pattern 130 for inductance and the terminals 132 a and 132 bfor joining to the quartz crystal resonator element 1 provided on onemain surface of the intermediate substrate 102 is wide. For this reason,in a case where the quartz crystal resonator element 1 is joined ontothe intermediate substrate 102, the excitation electrode 20 b of thequartz crystal resonator element 1 and the electrode pattern 130 forinductance do not overlap, and thus it is possible to prevent a floatingcapacitance between electrodes of the excitation electrode 20 b and theelectrode pattern 130 for inductance.

Modification Example 2 of Intermediate Substrate

FIGS. 11A to 11C show a modification example of the intermediatesubstrate, in which FIG. 11A is a schematic plan view when a structureof the intermediate substrate according to a third embodiment of theinvention is viewed from the top, FIG. 11B is a cross-sectional viewtaken along the line G-G of FIG. 11A, and FIG. 11C is a schematic planview when FIG. 11A is viewed from the bottom.

As shown in FIG. 11A, in an intermediate substrate 202 according to thepresent modification example, a configuration of one main surface sideof the substrate 215 is completely the same as the configuration of theintermediate substrate 2 of the embodiment shown in FIGS. 2A to 2C. Inother words, the substrate 215 is provided with an electrode pattern 230a for inductance, terminals 232 a and 232 b for joining to the quartzcrystal resonator element 1, and connection terminals 234 a and 234 b.

In addition, as shown in FIG. 11C, on the other main surface of thesubstrate 215, a lead electrode 233 b is drawn out from the connectionterminal 234 b and is connected to an electrode pattern 230 b forinductance which is formed in an inductance forming region.

The electrode pattern 230 b for inductance formed on the other mainsurface is formed in the same shape and arrangement so as to overlap theelectrode pattern 230 a for inductance formed on one main surface inplan view. In this way, it is possible to suppress a defect such asreduction in frequency variable sensitivity due to canceling-out ofinductances between the electrode patterns for inductance in a casewhere shapes or arrangements of the electrode patterns 230 a and 230 bfor inductance on both main surfaces are misaligned, for example, in acase where winding directions of the rectangular spiral shapes areopposite to each other.

The electrode pattern 230 a for inductance and the electrode pattern 230b for inductance formed on both main surfaces of the intermediatesubstrate 202 are electrically connected to each other at the center ofthe inductance forming region via an in-layer wire 237 such as athrough-hole. Thereby, it is possible to provide the intermediatesubstrate 202 in which the two electrode patterns 230 a and 230 b forinductance are connected in series to each other between the terminal232 b for joining to the quartz crystal resonator element 1 provided onone main surface and the connection terminal 234 b provided on the othermain surface.

According to the intermediate substrate 202 of the present modificationexample, two electrode patterns 230 a and 230 b for inductance areconnected in series to each other formed on both main surfaces of theintermediate substrate 202 are formed in a state of being connected inseries to each other. Thereby, it is possible to increase an effect ofincreasing a frequency variable width by the electrode patterns 230 aand 230 b for inductance without increasing the size of the intermediatesubstrate as compared with a case where an electrode pattern forinductance is provided only one main surface of the intermediatesubstrate.

Modification Example 2 of Quartz Crystal Resonating Element

FIGS. 12A and 12B show a modification example of the quartz crystalresonating element, in which FIG. 12A is a schematic plan view when astructure of the quartz crystal resonating element according to a thirdembodiment of the invention is viewed from the top, and FIG. 12B is across-sectional view taken along the line H-H of FIG. 12A.

As shown in FIGS. 12A and 12B, a quartz crystal resonating element 203according to the present modification example is formed by mounting thequartz crystal resonator element 1 on the intermediate substrate 202which is a modification example of the intermediate substrate 2 of theembodiment shown in FIGS. 2A to 2C. The terminals 232 a and 232 b forjoining to the quartz crystal resonator element 1 provided on one mainsurface of the intermediate substrate 202 are aligned with thecorresponding external connection terminals 22 a and 22 b of the quartzcrystal resonator element 1 and are joined thereto via a joining member40. In addition, the vibrating portion 12 of the quartz crystalresonator element 1 is disposed with a gap by the joining member 40 withrespect to one main surface of the intermediate substrate 202 on whichthe electrode pattern 230 a for inductance is formed.

Since, in the quartz crystal resonating element 203, the electrodepatterns 230 a and 230 b for inductance provided on both main surfacesof the intermediate substrate 202 are formed in a state of beingconnected in series to each other, it is possible to obtain a frequencyvariable width larger than in the quartz crystal resonating element 3 ofthe embodiment shown in FIGS. 3A and 3B.

Modification Example 3 of Intermediate Substrate

FIGS. 13A to 13C show a modification example of the intermediatesubstrate, in which FIG. 13A is a schematic plan view when a structureof the intermediate substrate according to a fourth embodiment of theinvention is viewed from the top, FIG. 13B is a cross-sectional viewtaken along the line I-I of FIG. 13A, and FIG. 13C is a schematic planview when FIG. 13A is viewed from the bottom.

An intermediate substrate 302 according to the present modificationexample includes, as shown in FIGS. 13A to 13C, a substrate 315, ashield electrode 340, terminals 332 a and 332 b for joining to thequartz crystal resonator element 1, connection terminals 334 a and 334b, and an electrode pattern 330 for inductance.

One main surface of the substrate 315 is a surface on which the quartzcrystal resonator element 1 is mounted, and is provided with the shieldelectrode 340, a pad electrode 341, the joining terminals 332 a and 332b, the connection terminals 334 a and 334 b, and lead electrodes 333 aand 333 b.

The other main surface of the substrate 315 is provided with anelectrode pattern 330 for inductance, a pad electrode 343, connectionterminals 334 a and 334 b, and lead electrodes 331 b and 336. Theelectrode pattern 330 for inductance and the connection terminal 334 bare electrically connected to each other via the lead electrode 336. Inaddition, an insulating film 55, for example, a silicon oxide film isformed on the electrode pattern 330 for inductance so as to prevent theelectrode pattern 330 for inductance and the lead electrode 336 frombeing short-circuited.

The connection terminals 334 a and 334 b, the lead electrodes 331 b and333 b, and the pad electrodes 341 and 343, formed on both main surfacesof the substrate 315, are respectively electrically connected to eachother via side electrodes 335 a, 335 b, 337 b and 342.

Since, in the intermediate substrate 302, the shield electrode 340 isformed on the surface on which the quartz crystal resonator element 1 ismounted, in a case where a quartz crystal resonating element is formedby stacking and joining the quartz crystal resonator element 1 and theintermediate substrate 102, it is possible to prevent influence of afloating capacitance between electrodes of the excitation electrode 20 bof the quartz crystal resonator element 1 and the electrode pattern 330for inductance by using the shield electrode 340.

In addition, in the intermediate substrate 302 according to the presentmodification example, the joining terminals 332 a and 332 b are formedon the surface on which the shield electrode 340 is formed; however, thejoining terminals 332 a and 332 b may be formed on the surface on whichthe electrode pattern 330 for inductance with a configuration ofpreventing a short circuit by using the insulating film 55 is formed.

In addition, in the same manner as the intermediate substrate 2 of theembodiment shown in FIGS. 2A to 2C, the electrode pattern 330 forinductance with a configuration of preventing a short circuit by usingthe insulating film 55 and the joining terminals 332 a and 332 b may beformed on the same surface, and the shield electrode 340 may not beformed.

Modification Example 3 of Quartz Crystal Resonating Element

FIGS. 14A and 14B show a modification example of the quartz crystalresonating element, in which FIG. 14A is a schematic plan view when astructure of the quartz crystal resonating element according to thefourth embodiment of the invention is viewed from the top, and FIG. 14Bis a cross-sectional view taken along the line J-J of FIG. 14A.

As shown in FIGS. 14A and 14B, a quartz crystal resonating element 303according to the present modification example is formed by mounting thequartz crystal resonator element 1 on the intermediate substrate 302which is a modification example of the intermediate substrate 2 of theembodiment shown in FIGS. 2A to 2C. The terminals 332 a and 332 b forjoining to the quartz crystal resonator element 1 provided on one mainsurface of the intermediate substrate 302 are aligned with thecorresponding external connection terminals 22 a and 22 b of the quartzcrystal resonator element 1 and are joined thereto via a joining member40. In addition, the vibrating portion 12 of the quartz crystalresonator element 1 is disposed with a gap by the joining member 40 withrespect to one main surface of the intermediate substrate 302 on which ashield electrode 340 is formed.

Since, in the quartz crystal resonating element 303, the shieldelectrode 340 is formed on the surface of the intermediate substrate 302on which the quartz crystal resonator element 1 is mounted, it ispossible to prevent adverse effects caused by a floating capacitancebetween electrodes of the excitation electrode 20 b of the quartzcrystal resonator element 1 and the electrode pattern 330 for inductancefrom being exerted on oscillation characteristics.

Further, if an intermediate substrate (not shown) in which the joiningterminals 332 a and 332 b are formed on a surface on which the electrodepattern 330 for inductance with a configuration of preventing a shortcircuit by using the insulating film 55 is formed is used in the quartzcrystal resonating element 303 of the present modification example, theelectrode pattern 330 for inductance is formed on the surface on whichthe quartz crystal resonator element 1 is mounted, and the shieldelectrode 340 is formed on the surface opposite to the IC chip 50.Therefore, in a case of forming a quartz crystal oscillator, it ispossible to prevent adverse effects caused by a floating capacitancebetween electrodes of the electrode pattern 330 for inductance and theIC chip 50 from being exerted on oscillation characteristics.

Further, if a quartz crystal resonating element is formed using anintermediate substrate (not shown) in which the electrode pattern 330for inductance with a configuration of preventing a short circuit byusing the insulating film 55 and the joining terminals 332 a and 332 bare formed on the same surface and the shield electrode 340 is notformed, and is used in a quartz crystal oscillator, it is possible toobtain characteristics equivalent to the quartz crystal oscillator 5 ofthe embodiment shown in FIGS. 5A and 5B.

Modification Example 1 of Quartz Crystal Oscillator

FIGS. 15A and 15B show a modification example of the quartz crystaloscillator, in which FIG. 15A is a schematic plan view when a structureof a quartz crystal oscillator according to the fourth embodiment of theinvention is viewed from the top, and FIG. 15B is a cross-sectional viewtaken along the line K-K of FIG. 15A. In addition, in FIGS. 15A and 15B,for convenience of description of an inner configuration of the quartzcrystal oscillator, a state in which the lid member is removed is shown.

In a quartz crystal oscillator 501 which is the present modificationexample, as shown in FIGS. 15A and 15B, the quartz crystal resonatingelement 303 which is a modification example of the quartz crystalresonating element 3 of the embodiment shown in FIGS. 3A and 3B ismounted, and thus the quartz crystal oscillator 501 is different fromthe quartz crystal oscillator 5 of the embodiment shown in FIGS. 5A and5B in a partial configuration of a package main body 60 b. In addition,description of the same configuration as the quartz crystal oscillator 5of the embodiment shown in FIGS. 5A and 5B will be omitted.

The quartz crystal oscillator 501 includes a package main body 60 b, alid member 70, the quartz crystal resonating element 303, and an IC chip50 in which an oscillation circuit exciting the quartz crystalresonating element 303 is mounted.

In the package main body 60 b, an element mounting pad 82 is formed onan upper surface of a third substrate 63 b in order to electricallyconnect a shield electrode 340 provided on the intermediate substrate302 of the quartz crystal resonating element 303 to a ground terminalwhich is one of mounting terminals 86 of the package main body 60 b. Inaddition, the mounting terminal 86 which is the ground terminal and theelement mounting pad 82 are electrically connected to each other viaconductors (not shown) formed inside the first substrate 61 and thethird substrate 63 b. The element mounting pads 81 are disposed so as tocorrespond to the connection terminals 334 a and 334 b formed on theintermediate substrate 302 when the quartz crystal resonating element303 is placed, and the element mounting pad 82 is disposed so as tocorrespond to a pad electrode 343 formed on the intermediate substrate302 when the quartz crystal resonating element 303 is placed.

The quartz crystal resonating element 303 is joined to the elementmounting pads 81 and 82 of the package main body 60 b by usingconductive joining member 42 and joining member 44 such as conductiveadhesives in a state in which the connection terminals 334 a and 334 bare aligned with the pad electrode 343.

The quartz crystal oscillator 501 in which the quartz crystal resonatingelement 303 having the shield electrode 340 is mounted can prevent afloating capacitance between electrodes of the excitation electrode 20 bof the quartz crystal resonator element 1 and the electrode pattern 330for inductance or the excitation electrode 20 b of the quartz crystalresonator element 1 and the IC chip 50, and thus has stable oscillationcharacteristics. Therefore, it is possible to provide a quartz crystaloscillator with a large frequency variable width.

Modification Example 1 of Quartz Crystal Resonator Element

FIGS. 16A and 16B show a modification example of the quartz crystalresonator element, in which FIG. 16A is a schematic plan view when astructure of a quartz crystal resonator element according to a fifthembodiment of the invention is viewed from the top, and FIG. 16B is across-sectional view taken along the line L-L of FIG. 16A.

A quartz crystal resonator element 101 which is a modification exampleof the quartz crystal resonator element 1 of the embodiment shown inFIGS. 1A and 1B includes, as shown in FIG. 16A, a quartz crystalsubstrate 110, excitation electrodes 120 a and 120 b, and externalconnection terminals 122 a and 122 b. The quartz crystal substrate 110includes a support portion 114 which is a fixed end and a vibratingportion 112 which is a free end. Here, the vibrating portion 112according to the present modification example indicates a region whichis interposed between mesa portions 116 formed on both main surfaces ofthe quartz crystal substrate 110. In addition, the support portion 114indicates a region between the vibrating portion 112 and the fixed end(the left side) of the quartz crystal resonator element 101. A pair ofexcitation electrodes 120 a and 120 b are provided so as to be oppositeto each other on both main surfaces of the vibrating portion 112. Inaddition, the external connection terminals 122 a and 122 b whichrespectively correspond to the excitation electrodes 120 a and 120 b areprovided on both main surfaces of the support portion 114, and theexcitation electrodes 120 a and 120 b are respectively electricallyconnected to the corresponding external connection terminals 122 a and122 b via lead electrodes 121 a and 121 b. In addition, the externalconnection terminals 122 a and 122 b provided so as to be opposite toeach other on both the main surfaces of the support portion 114 arerespectively electrically connected to each other via side electrodes123 a and 123 b.

Since the quartz crystal resonator element 101 has a mesa structure inwhich the mesa portions 116 are formed on both main surfaces of thequartz crystal substrate 110, coupling with a spurious profile can beprevented, and thus vibration energy of only the main vibration can beconfined. Therefore, it is possible to reduce CI and to thereby suppressa spurious frequency around a resonance frequency.

Modification Example 4 of Quartz Crystal Resonating Element

FIGS. 17A and 17B show a modification example of the quartz crystalresonating element, in which FIG. 17A is a schematic plan view when astructure of the quartz crystal resonating element according to thefifth embodiment of the invention is viewed from the top, and FIG. 17Bis a cross-sectional view taken along the line M-M of FIG. 17A.

As shown in FIGS. 17A and 17B, a quartz crystal resonating element 304according to the present modification example is formed by mounting aquartz crystal resonator element 101 which is a modification example ofthe quartz crystal resonator element 1 of the embodiment shown in FIGS.1A and 1B on the intermediate substrate 2. The terminals 32 a and 32 bfor joining to the quartz crystal resonator element 101 provided on onemain surface of the intermediate substrate 2 are aligned with thecorresponding external connection terminals 122 a and 122 b of thequartz crystal resonator element 101 and are joined thereto via ajoining member 40. In addition, the vibrating portion 112 of the quartzcrystal resonator element 101 is disposed with a gap by the joiningmember 40 with respect to one main surface of the intermediate substrate2 on which the electrode pattern 30 for inductance is formed.

Since, in the quartz crystal resonating element 304, the mesa portions116 are formed in the vibrating portion 112 of the quartz crystalresonator element 101, coupling with a spurious profile can beprevented, and thus vibration energy of only the main vibration can beconfined. Therefore, it is possible to provide a resonating element inwhich CI is small and a spurious frequency around a resonance frequencyis suppressed.

Modification Example 2 of Quartz Crystal Resonator Element

FIGS. 18A and 18B show a modification example of the quartz crystalresonator element, in which FIG. 18A is a schematic plan view when astructure of a quartz crystal resonator element according to a sixthembodiment of the invention is viewed from the top, and FIG. 18B is across-sectional view taken along the line O-O of FIG. 18A.

A quartz crystal resonator element 201 which is a modification exampleof the quartz crystal resonator element 1 of the embodiment shown inFIGS. 1A and 1B includes, as shown in FIG. 18A, a quartz crystalsubstrate 210, excitation electrodes 220 a and 220 b, and externalconnection terminals 222 a and 222 b. The quartz crystal substrate 210includes a support portion 214 which is a fixed end and a vibratingportion 212 which is a free end. Here, the vibrating portion 212according to the present modification example indicates a region whichis interposed between a bottom of a recess 216 formed on one mainsurface of the quartz crystal substrate 210 and a main surface on a sidewhere the recess 216 is not formed. In addition, the support portion 214is the thick portion interposed between both main surfaces of the quartzcrystal substrate 210 and indicates a region between the vibratingportion 212 and the fixed end (the left side) of the quartz crystalresonator element 201. A pair of excitation electrodes 220 a and 220 bare provided so as to be opposite to each other on both main surfaces ofthe vibrating portion 212. In addition, the external connectionterminals 222 a and 222 b which respectively correspond to theexcitation electrodes 220 a and 220 b are provided on both main surfacesof the support portion 214, and the excitation electrodes 220 a and 220b are respectively electrically connected to the corresponding externalconnection terminals 222 a and 222 b via lead electrodes 221 a and 221b. In addition, the external connection terminals 222 a and 222 bprovided so as to be opposite to each other on both the main surfaces ofthe support portion 214 are respectively electrically connected to eachother via side electrodes 223 a and 223 b.

Since the quartz crystal resonator element 201 has a reverse mesastructure in which the recess 216 is formed in the vibrating portion212, the vibrating portion 212 can be made to be very thin so as toachieve a high frequency. In addition, since mounting is performed onthe thick part which is integrally formed with the vibrating portion212, good resistance to impact or resistance to vibration can beexpected.

Modification Example 5 of Quartz Crystal Resonating Element

FIGS. 19A and 19B show a modification example of the quartz crystalresonating element, in which FIG. 19A is a schematic plan view when astructure of the quartz crystal resonating element according to thesixth embodiment of the invention is viewed from the top, and FIG. 19Bis a cross-sectional view taken along the line P-P of FIG. 19A.

As shown in FIGS. 19A and 19B, a quartz crystal resonating element 305according to the present modification example is formed by mounting aquartz crystal resonator element 201 which is a modification example ofthe quartz crystal resonator element 1 of the embodiment shown in FIGS.1A and 1B on the intermediate substrate 2. The terminals 32 a and 32 bfor joining to the quartz crystal resonator element 201 provided on onemain surface of the intermediate substrate 2 are aligned with thecorresponding external connection terminals 222 a and 222 b of thequartz crystal resonator element 201 and are joined thereto via ajoining member 40. In addition, the vibrating portion 212 of the quartzcrystal resonator element 201 is disposed with a gap by the joiningmember 40 with respect to one main surface of the intermediate substrate2 on which the electrode pattern 30 for inductance is formed.

Since, in the quartz crystal resonating element 305, since the recess216 is formed in the vibrating portion 212 of the quartz crystalresonator element 201, it is possible to provide a resonating element ofa high frequency, and since mounting can be performed on the thick partwhich is integrally formed with the vibrating portion 212, it ispossible to provide a resonating element with good resistance to impactor resistance to vibration.

Next, with reference to FIGS. 20 to 22, a detailed description will bemade of electronic apparatuses to which the quartz crystal resonatingelement which is an example of the resonating element according to thefirst embodiment of the invention is applied.

FIG. 20 is a perspective view illustrating a configuration of a mobiletype (or a notebook type) personal computer as an electronic apparatusincluding the quartz crystal resonating element which is an example ofthe resonating element according to the first embodiment of theinvention. In FIG. 20, a personal computer 1100 is constituted by a mainbody portion 1104 having a keyboard 1102 and a display unit 1106 havinga display portion 100, and the display unit 1106 is supported so as tobe rotatably moved with respect to the main body portion 1104 via ahinge structure portion. The personal computer 1100 includes the quartzcrystal resonating element 3, embedded therein, which functions as afilter, a resonator, a reference clock and the like.

FIG. 21 is a perspective view illustrating a configuration of a mobilephone (including PHS) as an electronic apparatus including the quartzcrystal resonating element which is an example of the resonating elementaccording to the first embodiment of the invention. In FIG. 21, a mobilephone 1200 includes a plurality of operation buttons 1202, an earpiece1204, and a mouthpiece 1206, and a display portion 100 is disposedbetween the operation buttons 1202 and the mouthpiece 1204. The mobilephone 1200 includes the quartz crystal resonating element 3, embeddedtherein, which functions as at least one of a filter, a resonator, andthe like.

FIG. 22 is a perspective view illustrating a configuration of a digitalcamera as an electronic apparatus including the quartz crystalresonating element which is an example of the resonating elementaccording to the first embodiment of the invention. In addition, in FIG.22, connection to an external apparatus is also briefly shown. Here, atypical camera exposes a silver halide photography film to light using alight image of a subject, whereas the digital camera 1300 performsphotoelectric conversion on a light image of a subject by using animaging device such as a Charge Coupled Device (CCD) so as to generatean imaging signal (image signal).

A display portion 100 is provided on a rear side of a case (body) 1302of the digital camera 1300 and performs display on the basis of animaging signal generated by the CCD, and the display portion 100functions a finder which displays a subject as an electronic image. Inaddition, a light sensing unit 1304 which includes an optical lens(imaging optical system), a CCD, and the like is provided on a frontside (the rear side in FIG. 22) of the case 1302.

When a photographer confirms a subject image displayed on the displayportion 100 and presses a shutter button 1306, an imaging signal of theCCD at this point is transmitted to and stored in a memory 1308. Inaddition, in this digital camera 1300, video signal output terminals1312 and input and output terminals 1314 for data communication areprovided on a side surface of the case 1302. Further, as shown in FIG.22, the video signal output terminals 1312 are connected to a televisionmonitor 1430 and the input and output terminals 1314 for datacommunication are connected to a personal computer (PC) 1440 asnecessary. Furthermore, an imaging signal stored in the memory 1308 isoutput to the television monitor 1430 or the personal computer 1440through a predetermined operation. The digital camera 1300 includes thequartz crystal resonating element 3, embedded therein, which functionsas a filter, a resonator, and the like.

Further, in addition to the personal computer (a mobile type personalcomputer) of FIG. 20, the mobile phone of FIG. 21, and the digitalcamera of FIG. 22, the electronic apparatus including the quartz crystalresonating element which is an example of the resonating elementaccording to the first embodiment of the invention is applicable to, forexample, an inkjet type ejection apparatus (for example, an ink jetprinter), a laptop type personal computer, a television, a video camera,a video tape recorder, a car navigation apparatus, a pager, anelectronic organizer (including a communication function), an electronicdictionary, an electronic calculator, an electronic gaming machine, aword processor, a workstation, a videophone, a security televisionmonitor, an electronic binocular, a POS terminal, a medical apparatus(for example, an electronic thermometer, a sphygmomanometer, a bloodglucose monitoring system, an electrocardiographic apparatus, anultrasonic diagnostic apparatus, or an electronic endoscope), afish-finder, various measurement apparatuses, meters and gauges (forexample, meters and gauges of vehicles, aircrafts, and ships), a flightsimulator, and the like.

FIG. 23 is a perspective view schematically illustrating an automobile2106 which is a specific example of a moving body. In FIG. 23, thequartz crystal resonating element 3 is embedded in an electronic controlunit 2108 which controls tires 2109, and is mounted in a car body 2107.

The resonator or the electronic device having the resonating elementaccording to the embodiments of the invention is mounted in theautomobile 2106, and is widely applicable to the electronic control unit(ECU) 2108 such as a keyless entry, an immobilizer, a car navigationsystem, a car air conditioner, an antilock brake system (ABS), an airbag, a tire pressure monitoring system (TPMS), engine control, a batterymonitor of a hybrid car or an electric car, and a vehicle dynamiccontrol system.

What is claimed is:
 1. A resonating element comprising: a base substratethat has first and second base terminals; a resonator element thatincludes a vibrating portion; first and second excitation electrodes; anintermediate substrate in which the resonator element is mounted so asto be spaced from the first and second excitation electrodes, theintermediate substrate being mounted to the base substrate, theintermediate substrate being spaced apart from the base substrate; and aspiral electrode pattern that is provided on the intermediate substrateand that has first and second ends, wherein the first base terminal, thefirst excitation electrode, and the first and second ends of the spiralelectrode pattern are electrically connected to each other, the secondbase terminal and the second excitation electrode are electricallyconnected to each other.
 2. The resonating element according to claim 1,wherein the spiral electrode pattern and the first and second excitationelectrodes are connected in series or in parallel to each other.
 3. Theresonating element according to claim 1, wherein the spiral electrodepattern and the first and second excitation electrodes are disposed soas not to overlap each other in a plan view.
 4. The resonating elementaccording to claim 1, wherein the spiral electrode patterns are providedon the upper and lower surfaces of the intermediate substrate and thespiral electrode patterns are connected in series to each other.
 5. Theresonating element according to claim 1, wherein the electrode patternis provided on one main surface of the upper and lower surfaces of theintermediate substrate, a shield electrode is provided on the other mainsurface of the upper and lower surfaces, and the other main surfacefaces to the first excitation electrode.
 6. The resonating elementaccording to claim 1, wherein the resonator element includes thevibrating portion; and an outer edge portion that is integrally formedwith an outer edge of the vibrating portion and is thinner than thevibrating portion.
 7. The resonating element according to claim 1,wherein the resonator element includes the vibrating portion; and anouter edge portion that is integrally formed with an outer edge of thevibrating portion and is thicker than the vibrating portion.
 8. Aresonator comprising: the resonating element according to claim 1; and apackage in which the resonating element is mounted by including theintermediate substrate mounted therein.
 9. A resonator comprising: theresonating element according to claim 2; and a package in which theresonating element is mounted by including the intermediate substratemounted therein.
 10. An electronic device comprising: the resonatingelement according to claim 1; a package in which the resonating elementis mounted by including the intermediate substrate mounted therein; andan oscillation circuit that excites the vibrating portion.
 11. Anelectronic device comprising: the resonating element according to claim2; a package in which the resonating element is mounted by including theintermediate substrate mounted therein; and an oscillation circuit thatexcites the vibrating portion.
 12. An electronic device comprising: theresonating element according to claim 5; a package in which theresonating element is mounted by including the intermediate substratemounted therein; and an oscillation circuit that excites the vibratingportion, wherein the shield electrode is connected to a ground terminalof the package.
 13. An electronic apparatus comprising: the resonatingelement according to claim
 1. 14. An electronic apparatus comprising:the resonating element according to claim
 2. 15. A moving bodycomprising: the resonating element according to claim
 1. 16. A movingbody comprising: the resonating element according to claim 2.